I for one have never liked that crossover design. I know it's theoretical intent but it's very power wasteful for what little purpose it serves.

Over the years I've redesigned a number of those types of circuits to simplify them and reduce their power losses by taking out the resistors that ran parallel to the speaker circuit. The speaker units never showed any real change in performance other that being a bit louder in the mids and highs for the given power put into them.

Can you post your circuit? I need to build one.

 

Can you post your circuit? I need to build one.

Pick which one you want.

https://www.diyaudioandvideo.com/Calculator/SpeakerCrossover/

I prefer 1st or 2nd order Butterworth designs for their overall simplicity and efficiency along with properly matched speakers.

Any speaker that has a unusual issue with frequency peaks or lows, due to realy bad physical component choices and design, is best compensated for with active filtering or processing ahead of the amplifier.

A good multiband and parametric equalizer can clean up a poor sounding speakers performance way better than any passive LCR circuits ever will.

 

Pick which one you want.

https://www.diyaudioandvideo.com/Calculator/SpeakerCrossover/

I prefer 1st or 2nd order Butterworth designs for their overall simplicity and efficiency along with properly matched speakers.

Any speaker that has a unusual issue with frequency peaks or lows, due to realy bad physical component choices and design, is best compensated for with active filtering or processing ahead of the amplifier.

A good multiband and parametric equalizer can clean up a poor sounding speakers performance way better than any passive LCR circuits ever will.

I was looking for a 3 way like the OP's. But I found a good one on line.
Thanks!

 

I was looking for a 3 way like the OP's. But I found a good one on line.
Thanks!

The internet knows more than all of us do. You just have to ask it the right questions first.

For me for 3 - 4 way speaker setups I just used a combination of a high and low pass butterworth circuits in series for the mid range.

As long as the speaker to speaker crossover cut off slope overlaps Vs the individual speaker's frequency response curves in that frequency band are taken into consideration it's pretty easy to get a good near linear frequency response from the overall set.

Given that, you may find that with each two speakers where you want a crossover frequency of say 2000 HZ you might have to separate the high and low pass points going to each speaker by a few hundred hertz to get an actual smooth frequency response from the set in the 2000 Hz sound range.

I think that's where the simple Butterworth crossover circuit gets a bad rap for simply because the designer assumes both speakers magically drop their power outputs right at the frequency they choose when in fact they don't and they don't compensate for the band of frequency response overlap both speakers will have near their ideal cut off point.

 

165W @ 8 ohms
That's 4.54 amps RMS per channel.
(2) 4 ohm in parallel makes 2 ohms
In series with the midrange speaker.
If the midrange speaker carries half the wattage, that's 3.2 watts dissipated by 20 watts worth of resistors.
If all the power went to the midrange speaker and the owner played it maxed out continuously, that would be 41.25 watts into 20 watts worth of resistors.
Considering average power content in music and a bass speaker taking half the power, the math doesn't demonstrate how those resistors can get too hot to survive.

This is, "not a problem" unless something else is broken.
Does the stereo sound right? If so, this is an imaginary problem.
If not, something else is wrong.[/QUOTE

 

Thank

 

I need to know how to fix this crossover circuit boards.
These speakers are bi ampable.
I run two speaker wires to each speaker.
The woofer operates off of its own circuit board - it does not overheat and works perfectly.
The tweeter and the two midranges operates off of another circiut board - schematic was posted June 15 .
The tweeter and the low midrange circuits have very little heat .
The midrange circuit with the two 10 watt parallel resistors get blistering hot at 1/3 to 1/2 volume and after a short period of time the upper midrange speaker stops working.
The resistors do not burn up but I have had to put in new capacitors.
When that speaker works it sounds perfect.
Why do I only have the problem with the upper midrange???
Both speakers have identical problem.

 

I need to know how to fix this crossover circuit boards.
These speakers are bi ampable.
I run two speaker wires to each speaker.
The woofer operates off of its own circuit board - it does not overheat and works perfectly.
The tweeter and the two midranges operates off of another circiut board - schematic was posted June 15 .
The tweeter and the low midrange circuits have very little heat .
The midrange circuit with the two 10 watt parallel resistors get blistering hot at 1/3 to 1/2 volume and after a short period of time the upper midrange speaker stops working.
The resistors do not burn up but I have had to put in new capacitors.
When that speaker works it sounds perfect.
Why do I only have the problem with the upper midrange???
Both speakers have identical problem.

If it is happening at 1/3 power only 4 possibilities.
R5, C4, C10 or the speaker are shorting out at higher power.

 

If it is happening at 1/3 power only 4 possibilities.
R5, C4, C10 or the speaker are shorting out at higher power.

Can you please recheck the schematic and I can see R5 & C10 but what about C4?
Why would both speakers have the identical problem? Is there a design defect? Could I update the circuit board to make it better & stop the heating and prevent the midrange from burning out?

 

Can you please recheck the schematic and I can see R5 & C10 but what about C4?
Why would both speakers have the identical problem? Is there a design defect? Could I update the circuit board to make it better & stop the heating and prevent the midrange from burning out?

My guess is the resistors are not as hot as you think they are, but you say the speaker stops working. Is that correct?
If it's just the heat that is bothering you you could replace them with the same resistance but rated for higher power.
http://www.mouser.com/ds/2/303/res_200-275765.pdf
I think if the little cap were shorted it would just blow apart.

 

........I think that's where the simple Butterworth crossover circuit gets a bad rap for simply because the designer assumes both speakers magically drop their power outputs right at the frequency they choose when in fact they don't and they don't compensate for the band of frequency response overlap both speakers will have near their ideal cut off point.

Isn't that one of the purposes of a Linkwitz-Riley filter, to give a smooth handoff between the two speakers without any peak through the crossover?

 

Isn't that one of the purposes of a Linkwitz-Riley filter, to give a smooth handoff between the two speakers without any peak through the crossover?

Possibly. It's been ~25 years since I played with that type of audio stuff in detail to any heavy degree.

Once I got to the point of being able to multi amp the systems I worked with and was able to handle everything with off the shelf pre amp crossovers and signal processing gear building post amplifier crossover stuff pretty much ended for me beyond repairing the odd bad solder connection or tweaking things to work with a different impedance speaker.